Unfortunately, Obama has responded to the latest incident by following the same failed strategy as his predecessors when confronted with drug war losses: a stronger fight against drugs.

Though the deaths are the first in which Mexican drug cartels appear to have so brazenly targeted and killed individuals linked to the U.S. government, illicit drug trade violence has killed some 18,000 people in Mexico since President Calderon came to power in December 2006—more than three times the number of American military personnel deaths in the Iraq and Afghanistan wars combined.

The carnage only shot up after Calderon declared an all-out war on drug trafficking upon taking office. After more than three years, the policy has failed to reduce drug trafficking or production, but it is weakening the institutions of Mexican democracy and civil society through corruption and bloodshed, which are the predictable products of prohibition.

The 29 people killed in drug-related violence this weekend in a 24 hour period in the state of Guerrero sets a dubious record for a Mexican state. And an increasing number of Mexicans, including former Mexican Foreign Minister Jorge Castañeda, are calling for a thorough rethinking of anti-drug policy in Mexico and the United States that includes legalization. Legalization would significantly reduce drug cartel revenue and put an end to an enormous black market and the social pathologies that it creates.